In the past, for example, an I2C (Inter-Integrated Circuit) has been often used as a bus IF (Interface) used for communication between a plurality of devices via a bus in a board on which the plurality of devices are mounted.
Further, in recent years, an increase in the speed of the I2C is desired to be achieved, and an I3C (Improved inter Integrated Circuit) is being prescribed as the next-generation standards. In the I3C, a master and a slave are capable of performing bidirectional communication by using two signal lines. For example, data transfer (write transfer) from the master to the slave and data transfer (read transfer) from the slave to the master is performed.
For example, in Japanese Patent Application Laid-open No. 2000-99448, a digital data processing system in which a host processor and a sub-system controller are connected to each other by the I2C is disclosed. Further, in Japanese Patent Application Laid-open No. 2002-175269, a method of realizing a communication protocol arranged in the layered state on the upper part of a standard I2C protocol is disclosed.